kinematic_model.cpp

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 *  Author: Dula Nad
 *  Created: 01.02.2010.
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#include <labust/simulation/kinematic_model.h>
#include <labust/math/NumberManipulation.hpp>

using namespace labust::simulation;

KinematicModel::KinematicModel():
    dT(0.1),
    pos0(vector3::Zero()),
    quat0(1,0,0,0),
        quat(quat0),
    pos(pos0),
    current(vector3::Zero())
{
        this->init();
};

void KinematicModel::step(const vector& nu)
{
        //Assemble the linear and angluar velocity transformation matrices
        using namespace Eigen;
        pos += dT*(quat.toRotationMatrix()*nu.block<3,1>(0,0) + current);

        Eigen::Matrix<double,4,3> angMat;
        angMat<<quat.w(),-quat.z(),quat.y(),
                        quat.z(),-quat.w(),-quat.x(),
                        -quat.y(),quat.x(),quat.w(),
                        -quat.x(),-quat.y(),-quat.z();
        angMat = 0.5*angMat;
        Eigen::Matrix<double,4,1> dq=dT*angMat*nu.block<3,1>(3,0);
        quat.coeffs() += Eigen::Quaternion<double>(dq(3), dq(0),dq(1),dq(2)).coeffs();
        quat.normalize();
}